| Mahler9th |
07-02-2023 08:03 AM |
"It is amazing to me to see in the picture above how there is almost no overlap of the Ti ring and the carbon tube (maybe 10-20mm at most?) - the damn thing is essentially butt glued in place. What a joke. "
Others have used a similar approach.
See links at posts 448 and 449.
https://apps.dtic.mil/sti/citations/ADA273061
" Title: Adhesive Bonded Joint With Improved Cyclic Fatigue Life for Alumina- Ceramic Cylinders and Hemispheres. Fourth Generation Housings "
"A series of 20-inch-diameter monocoque cylinders of 94-percent alumina-ceramic have been pressure tested to determine their structural performance under repeated pressurizations to 9,000 psi external design pressure when their ends are encapsulated in epoxy-filled Mod 1 titanium or aluminum end caps. Naval Ocean Systems Center NOSC Type Mod 1 titanium end caps provided an order-of-magnitude improvement in cyclic fatigue life for the ceramic cylinders over previously tested Mod 0 end caps. The cyclic fatigue life of 20-inch OD by 18.63-inch ID by 30-inch L by 0.685-inch t ceramic cylinders with 0.5-inch weightdisplacement ratio, the ends of which were encapsulated with epoxy adhesive in Mod 1 titanium end caps, exceeded 400 cycles to 9,000 psi that generated inside the cylinder compressive membrane stresses of 136,000 psi magnitude in hoop and 68,000 psi in axial direction. At these stress levels, the shell of the monocoque cylinder can tolerate imperfections in the shape of spherical 0.063-inch and oblong cavities 0.063-inch by 0.187-inch located below, or on, the shell surface, provided that they are at least two inches away from the ends. The payload-carrying ability of 94-percent alumina- ceramic monocoque cylinders with above dimensions is approximately four-times larger, then, of rib-stiffened titanium cylinders with the same external dimensions and pressure rating. Ceramics, External pressure housing, Ocean engineering."
Author was considered and expert.
Other experts were involved.
Ceramic cylinder.
Not clear whether this area was what failed on Nereus.
Not clear whether Titan used some of the same or similar engineering design principals, processes, materials et cetera.
Not clear what tests were done or what, if any design parameters were extrapolations for either submersible.
Let's see what is learned by experts.
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